Mice Sing Love Songs With Jet Engine-Like Voice

Mice use ultra-high pitched squeaks for courting their mate and territorial defense, sounds that are too high in frequency for human ear to detect. These high pitched sounds have something in common with an engine. New research has discovered that mice make ultrasonic bleeps by creating a small air jet within their windpipes that employs a mechanism that has been previously observed only in jet engines or high-speed subsonic flows.

No one knew how mice managed to produce such sounds until now. Biologist Coen Elemans of the University of Southern Denmark led a team of researchers to study these sounds produced by mice and used high-speed cameras to click the pictures of mice's voice boxes, known as the larynx, as the mice produced their vocalizations, according to Live Science.

Two contradicting theories had been put forward to explain how the mice created these ultrasonic vocalizations. The first one suggested that as a result of vocal-cords vibrating superficially, such ultrasonic squeaks are produced. However, the ultra-high speed videos used by researchers showed that the vocal cords did not vibrate even superficially.

The researchers then switched to another hypothesis which stated that a small air jet originates in the windpipe of the pipe that flows against the inner walls of the larynx. The air waves then bounce back from the wall and travel upstream into the jet of air, thus creating a feedback loop that leads to these whistling sounds.

"Mice don't use vibrating vocal folds in their larynx to make these ultrasonic sounds. Instead they point a small air jet coming from the windpipe against the inner wall of the larynx", says Dr. Elemans

Most fascinating fact about these love songs sung by mice is that this mechanism is known to work only in supersonic flow applications, like that of vertical landing or take off with jet engines. Mice might be doing something quite clever and complicated to produce their love songs.

It is now being believed that all mice across the globe use this really cool technique of ultrasounds to communicate, but humans have very little knowledge about it. The more researchers understand how mice create their love songs, the easier it will become to understand and explain what happens in the brain of a mouse which has the same genetic mutation as a human who suffers speech or social disorder.